"Is IT's input really necessary nowadays?"
MarketingA exists to market CompanyA's ProductA to CompanyB.
ManagementB exists to maximize CompanyB's shareholder profit.
ManagementB has no clue how stuff actually works, they are purely money motivated.
MarketingA takes advantage of this, using obfuscation (and sometimes outright lies) to convince ManagementB to buy into whatever product CompanyA is building.
When TechnologyTrackFolksB suggest to ManagementB that they have been taken in by MarketingA, and are making a drastic mistake because (insert technical reason here), ManagementB goes with the explanation offered by MarketingA, because it is easier for ManagementB to understand the outright bullshit MarketingA has told them.
When Marketing convinces Management that people with an actual clue as to how things work in the real world (and in fact were actually HIRED to make decisions in that aspect of running the business!) are "only trying to confuse them" ... well, do the math(s).
This whole "cloud" meme is due to die a slow, painful death. Preferably sooner, rather than later.
 Worse than daft. It doesn't even scale on first blush ... Consider: if IBM, HP, Microsoft, Google and Yahoo are all trading *AAS, do none of them actually have the IT department involved in making IT decisions? Boiling it down to basics, *AAS is a marketing term, not an IT term. It doesn't really work over the long-haul in the real world ... Not with CPU, memory, disk and bandwidth as cheep to own outright as they are today. Marketing and Management are not IT, and shouldn't be making IT decisions. They quite simply aren't equipped to make those decisions, any more than the average accountant or Fuller Brush Man is equipped to spec out a new data center.